Johnny50

Does anyone know what the maximum data speed is with CAT 5 cabling ?

We've just upgraded to Cisco switches, which are all gigabyte capable.

We're running 100mb over the lan already, but not sure if cat5 can handle the jump up to 1000mb ??

Anyone ??

Thanks
Johnny.

Mogsi

CAT5 is 10/100..

CAT5e or CAT6 cabling is desgined for gigabit connections.....



[Edited by Mogsi - 12/4/2003 9:59:45 AM]

SiCotty

Your Cisco switches should work fine at 10/100/1000 over standard cat5 UTP cables.

Simon

PS. Which switches do you have

http://www.cisco.com/en/US/tech/tk389/tk214/tech_digest09186a0080091a86.html

[Edited by SiCotty - 12/4/2003 10:34:03 AM]

tonybooth

Cat5 will need retesting to TSB-95 if you intend to run Gigabit Ethernet over it. If you need more details as to why call me.

TONY
07803 955600

Johnny50

Cheers for the replys fellas.

I'll go check what switches we have...cant remember the model.
We're a fairly large site, with a lot of cabling, so not sure if it will be cost effective to move up to gigabit or not.

Will get back to you with switch model.

Monkeh

We have 20 servers all connecting to a cisco 4006 switch, we are currently using Cat5E, now although the connection speed is reporting 1000mb/s we only ever seem to get 20 megabytes/sec throughput.

I have got some cat 6 cable and will be trying a couple of the servers on this to see if we can up the performance. (in a couple of weeks)

The Nic's are Intel 1000XT ver2 and are running on the 100mhz pci64 slot.

SiCotty

What Sup are you using, what density line card is it. You also have to consider is are the server and the gige NIC man enough to fill the pipe. Most TCP/IP driver operations are performed by the CPU.

When looking at data throughput you need to look at what is happening on the link. GigE uses 8b10b encoding, then you need to add the Ethernet header, then the IP header, then the TCP or UDP header, then the application layer header, then the actual data.

You also need to consider how the application is working and what both sides of the link are doing.

I would consider 20 Megabytes of throughput not bad at all.

Si

dsmith

"Reporting 1000mb/s we only ever seem to get 20 megabytes/sec "

1000 mb/s = BITS /sec

20 MBytes/s = 160 Mbits/s. If the 20 megabytes is real data a conservative estimate would be an additional 10% protocol overhead so so your link is running at nearly 200Mbits/sec

Check the specs on your cards/cable/switch. Gigabit Ethernet does not always mean 1000Mbits/s.

For a single data transfer various factors come into play in the inner wokring of TCP/IP and whatever higher level protocol is being used for the data transfer. To get a pair of servers doing more than that back to back will prob take some fine tuning of OS, NIC Drivers and disk sub-systems.

Deano